Given that p53null-BasalEx tumors are counterparts for the human basal-like subtype (Pfefferle et al., 2013) and that p53null-LuminalEx tumors show features of all three aggressive human subtypes (i.e. basal-like, HER2-enriched and luminal B), we investigated The Cancer Genome Atlas (TCGA) DNA copy-number dataset to determine whether these spontaneous murine genetic events were also enriched in human basal-like breast tumors to highlight conserved features across species (Cancer Genome Atlas Network, 2012). The gene discussed is ERBB2; the disease is breast neoplasm.